The present invention relates to a writing utensil such as a fountain pen, or in particular a cartridge pen, a pencil, a ball point pen, a felt tip pen etc. but in each instance being provided with a replaceable erasing portion or assembly which is located at the end of the pen remote from the nib or writing tip; the erasing portion or assembly includes an erasing cartridge with an erasing tip and is covered by means of an end cap fitted to the barrel of the utensil and both the barrel of the utensil and the end cap are designed to accommodate and seal the erasing tip.
A utensil realized as a fountain pen of this kind is known from German petty patent (utility model) 83 17 634. This writing implement makes possible the use of the erasing tip either together with the pen or as a separate item. The particular kind of pen has proven to be of practical value but it can be seen as disadvantageous that a seal must be present both in the barrel of the pen and in the end cap to provide the sealing for the erasing tip. Sealing however is an absolutely essential feature or function to be effective whereever and whenever the erasing part is not in use because of the erasing fluid that may evaporate quite easily through the wick.
The seals, which are provided in the form of a sealing cap in the barrel of the pen and in the end cap, or provided with a relatively large cavity due to the space required for the erasing cartridge and, therefore, the disadvantage arises that erasing fluid can evaporate into this cavity. Moreover, it can also be seen as disadvantageous that spare erasing parts for the fountain pen have to be fitted with their own protective cap until they are used and then the user has to remove and throw away the protective cap before the erasing parts are changed.